International AIDS Society Conference Update

Male circumcision as a prevention method?

Study was controversial from Day One

Investigators presented evidence at the International AIDS Society (IAS) conference in Rio de Janeiro, Brazil, in late July that male circumcision helps to reduce the risk of HIV infection among men who have sex with women.

The study showed that circumcised men were more than 60% less likely than uncircumcised men to be infected with HIV when having sex with infected female partners. Eighteen men in the circumcised intervention arm became infected, compared with HIV infection among 51 men in the uncircumcised control arm.1

However, the news was not welcomed by all quarters. Anti-circumcision activists quickly called on the United Nations to classify male circumcision of children younger than age 18 as a human rights crime. The group, called (A Bill to End Male Genital Mutilation in the U.S.), compares male circumcision to female genital mutilation.

The study enrolled more than 3,000 men, ages 18-24, in South Africa, in a region where male circumcision is chosen by about 20% of the male population at a median age of 17 years, reports Bertran Auvert, MD, PhD, professor at the University of Versailles in France.

Investigators had no trouble recruiting men in South Africa for the study because the volunteers wanted to be circumcised by medical doctors, he says.

"Circumcision was not something completely new or something we had to explain; it was something where the context was favorable for the trial," Auvert says.

About halfway through the trial, an interim analysis showed that the circumcision intervention had a very strong effect on HIV prevention, so the trial was stopped so that all of the male volunteers could be offered a safe circumcision, he reports.

"In this case, you don’t have to wait until the end of the trial because it’s unethical to continue if you can already decide the results of your trial," Auvert explains.

Ironically, he was contacted before the study began by a group of U.S physicians opposing male circumcision who told him that no matter what evidence his trial discovered, circumcision would have no impact on what the group thinks of circumcision, Auvert recalls.

"There view was not a very scientific position," he says.

The South Africa circumcision study was the first of three randomized controlled trials to study the preventive potential of male circumcision. Two other trials are under way in Kenya and Uganda, Auvert reports.

Also, studies of sexually active men in India have found that while circumcised men still become infected with HIV, they were infected at a rate of eight times less than uncircumcised men.

"I think the study was well received in IAS in Brazil because a rather large controlled trial has high scientific value," Auvert says. "It’s a very good piece of evidence, but before using it as a new prevention method for HIV, we need some more evidence from other places."

Although there has been some speculation and observational data that male circumcision might reduce the risk of HIV infection since the mid-1980s, it’s taken 20 years for the first controlled clinical trial to weigh in on the debate, partly because researchers had always assumed that sexual behavior differences accounted for the differences in HIV prevalence in Africa, he notes.

"I think nobody wanted to do a circumcision study or had the courage to do it, despite a lot of evidence that we had from observational studies since 1986," Auvert says.

For instance, HIV researchers long have known that countries such as Zimbabwe and South Africa, where a majority of men are uncircumcised, have high HIV prevalence when compared with men in Senegal and North Africa, where circumcision is commonplace, he points out.

While it’s still too early to advise men in sub-Saharan Africa to become circumcised as an HIV prevention strategy, this may one day be a possibility, Auvert notes.

"I think we’ve done a big scientific step, and we’ve done a small typical step, and we have to wait for the results from at least one of the other trials," he says. "If we see protective effect in one other place, plus all of the observational studies done in India, then I think circumcision could be added to the existing prevention tools like condom use and reducing sexual risk behavior and so on."

Also, it’s important to emphasize that while male circumcision may reduce risk of HIV infection, it isn’t completely protective. If circumcised men continue to have sex without using condoms with HIV-infected women, they may become infected, Auvert says.

"And the danger is the other prevention tools would be used less because circumcision is a new prevention tool, if it’s proven effective in other places," Auvert says.

In the meantime, health professionals should make certain that safe male circumcision is made available where it is needed and desired, not just for HIV prevention, he notes.

"I think it’s a responsibility of the countries to offer safe circumcision," Auvert says.


  1. Auvert B, et al. Impact of male circumcision on the female-to-male transmission of HIV: Results of the intervention trial: ANRS 1265. Abstract TuOa0402. Presented at the IAS Conference on HIV Pathogenesis and Treatment. Rio de Janeiro, Brazil; July 2005.